Wireless telegraphy.



ne. slMPsoN. WIRELESS TELEGRAPHY.

APPLICATION FILED MAY 27| 1914.

Patented Sept. 11, 1917/.

Petz/fak? me e m Lw: 1 L, d Z 2/ Fectzlfzjer /3 FREDERICK G. SIMPSON, or SEATTLE, WASHINGTON.

WIRELESS TELEGRAPHY.

Specification of Letters Patent.

Patented Sept., 11, 1917..

Application led May 27, 1914. Serial No. 841,183.

To all whom t may concerti:

Be it known that I, FREDERICK G. SIMP- soN a citizen of the-United States, residing eattle, in.l the county of King and State of Washington, have invented certain new and useful Improvements in Wireless Telegraphy, o-f which the following is a specification.

This invention relates to radio telegraph and telephonefsystems.

The principal object of the invention is to provide improved means for charging the condensers used in connection with apparatus of this character and' thereby to enable the charging currents to pass into the condensers but preventing the discharge from the latter through the charging circuit.

With the above and other objects in view, the invention consists in certain novel arrangements of details and combinations of parts hereinafter fully described, illustrated in the accompanying drawings, and specifically claimed.

In the accompanying drawings:

Figure 1 is a diagrammatic view showing one form of my apparatus wherein -an interrupter is used and direct current employed.

Fig. 2,is a View of an arrangement using a transformer and, alternating current together with a rectifier.

Fig. 3 is a modiedform of the arrangement disclosed in Fig. 2.-

Fig. 4 is a modified form of the arrangement shown in Fig. 1.' Fig. 5 is a second modification of the rangement shown in Fig. 2.

Fig. 6 discloses a still further modification of the arrangement shown in Fig. 2.. 1

Similar reference characters vdesignate corresponding parts in the diii'erent views.

In Fig. l-the reference numeral 1 desig- .nates a source of direct current, 2 atelegraph key. or other signaling device, by which the current from said -source is controlled, 3 an interrupter of anysuitable type, arran ed to open and close the circuits 1, 3, 4, 5, 1 and 1, 3, 6, 17, periodically. 4'and 6 are condensers; 5 an inductance coil, forming vthe primary of an oscillation transformer, o which 7 is'the secondary coil connected in circuit with the antenna 8 and the earth 9.

In Fig. 2, 10 is the source of alternating current supply, 11 and 12 being the primary and secondary, respectively, of atransformer whereby the'electric potential of the current is either raised or lowered. 13 is an alter- Y nating current rectifier 'of a kind which sup'- presses one-half of the alternating current wave. All other parts are the same as in Fig. 1.

In Figs. l, 2 and 3 the circuit including condensers 4 and 6, and inductance 5, is herein designated oscillation circuit. In Figs. 4, 5 and 6, antenna 8 and earth 9 replace condenser 6 in the oscillation circuit.

In the systems shown in Figs. 1 and 4, the inductance and capacity in the respective circuits 1, 2, 3, 4, 5, 17 should be so proportioned as to bring about a condition of reso# nance in the circuit mentioned at the frequency of interrupter 3. Circuits 12, 13, 4, 5, 17 in Figs. 2 and 5 and the circuits 14, 16, 4, 5, 17 and 15, 16, 4, 5, 17 in Figs. 3 and 6, should also be so proportioned as to inductance and capacity as to be resonant at the frequency of the charging current in condenser charges per second.

' It is evident that the period of oscillation of the oscillation circuit shown in Figs. 1, 2 and 3 may be varied at will between wide limits by providing a form of variable condenser for condenser 6..

It is a well-known fact that if a condenser be placed in a charging'circuit, said charging circuit having resistance, and there being a constant electro-motive force applied at the terminals of the condenser through the medium of the charging circuit, a finite length of time will elapse before the full difference o f potential will be created between the terminals of the condenser.

In practice as pertaining to the herein illustrated examples I prefer to so construct interrupter 3, and rectiiers 13vand 16, as to permit the ilow of a charging c urrent into condenser 4 for a sufficient period of time, during each charging interval, to create a diEerence of potential at the ternunals of condenser 4 slightly less than the diiference of potential impressed thereon 1f the inductance 5 were omitted from the circuit. Condenser 6' is usually of much'lowei' vcapacity than condenser 4; therefore, as 1t is subjected to the potential of the charging circuit for the same length of time as condenser 4, it will reach the potential thereof (practically) prior to the end of the period of charge. The action of inductance 5, however, owing to the law of resonance, and to its inertia eect upon the current ies lll@

drawn from the charging circuit, greatly modifies the potential difference at the terminals of condenser 4, thereby producing, at the cessation of the charge, a condition of unstability in the oscillation circuit, consisting of condenser 4, inductance 5, and condenser 6 in Figs. 1, 2 and 3; and condenser 4, inductance 5, earth 9 and antenna 8 in Figs. 4, 5 and 6, the interrupter 3 being opened at the instant of maximum charge. This condition of unstability is the initial cause of a current which oscillates within the oscillation circuit in accordance with the Well Vknown principles of resonance; said oscillations continuing until a point of electrical equilibrium 'is reached. With l.the possible exception of slight residual charges,

the entire energy stored in the condensersl and inductances, is dissipated by the action of the oscillating current in overcoming the resistance of the oscillation circuit, and by radiation from antenna 8.l v

In practice interrupter 3, and rectifiers 13 and 16 may be any of several well known types. Either mechanical, electrolytic, gaseous arcs, or others may be used. It is necessary for the attainment of the best possible results in the operation of a transmitting station, of which my arrangement of circuits and` apparatus form a. part, that the period, during which charging current is permitted to flow into' the condensers shall be limited, as hereinabove set forth. This result can be easily accomplished with interrupters and rectiiers of the mechanical type, as close adjustment of the periods of make and break is easily secured in interrupters and rectiiers of such type by purely mechanical means. l

Electrolytic interrupters and rectiers are, to a large extent, inherently self-regulating in this respect, and if properly proportioned, will give very satisfactory results when incorporated in the hereinbefore described system of circuits. Gaseous rectiers of the mercury vapor type are especially adaptable to mycircuits when the source fof power supplied is alternating.v

This is largely due to the possibility of constructing mercury vapor rectiers for operation at potentials of 10,000 volts or higher. The losses therein when operated at fairly high potentials are so low as to be almost negligible.

It is evident that changes can be made in the arrangement of the circuits illustrated and described without departing from the scope of my invention as expressed in thedenser, a conductor connecting the third' pole of the rectifier and the condenser, a second transformer primary connected in series to the condenser, a conductor connecting the transformer secondary and -the second transformer primary, a second condenser, a connection between the first conductorland second condenser, and a connection between the second condenser and second conductor.

Signed at Seattle, Wash., this 19th day of May, 1914.

FREDERICK G. SIMPSGN. Witnesses: l

E. PETERSON, HORACE BARNES. 

